A Thermoelectrically Cooled nBn Type-II Superlattices InAs/InAsSb/B-AlAsSb Mid-Wave Infrared Detector

Herein, an nBn barrier mid-wave infrared InAs/InAsSb (xSb = 0.4) type-II superlattice (T2SL) detector operating in the thermoelectrical (TE) cooling condition is reported. AlAsSb (Sb-composition, xSb ≥ 0.975) is shown not to introduce an additional barrier in the valence band in the analyzed temperature range (≥200 K) reached by four-stage TE cooling in nBn barrier architectures with a T2SL InAs/InAsSb active layer. The dark current and photocurrent produced are analyzed in relation to the barrier and contact layer doping, with the Sb composition of the barrier indicating the optimal architecture. The results of the simulation are compared with the experimental results of the HgCdTe and InAsSb nBn barrier detectors. A detectivity of ≈1010 cmHz1/2 W−1 at 200 K is reported without an immersion lens (≈1011 cmHz1/2 W−1 is reported for an immersed detector).